export default{
  namespaced: true,
  
  state: () => ({
    //购物车的数组，用来存储购物车中每个商品的信息对象
    //每个商品的信息对象，都包含如下6个属性：
    //{goods_id,goods_name,goods_price,goods_count,goods_small_logo,goods_state}
    // cart: []
    cart: JSON.parse(uni.getStorageSync('cart') || '[]')
  }),
  
  mutations: {
    addToCart(state,goods){
      const findResult = state.cart.find(x => x.goods_id === goods.goods_id)
      // console.log(findResult)
      
      if(!findResult){
        state.cart.push(goods)
      }else{
        findResult.goods_count ++ 
      }
      
      //通过commit方法，调用m_cart命名空间下的saveToStorage方法
      this.commit('m_cart/saveToStorage')
      
      // console.log(state.cart)     
    },
    saveToStorage(state){
      uni.setStorageSync('cart',JSON.stringify(state.cart))
    },
    //更新购物车中商品的勾选状态
    updateGoodsState(state,goods){
      
      const findResult = state.cart.find(x => x.goods_id === goods.goods_id)
      
      if(findResult){
        findResult.goods_state = goods.goods_state
        this.commit('m_cart/saveToStorage')
      }
    },
    //更新商品的数量
    updateGoodsCount(state,goods){
      const findResult = state.cart.find(x => x.goods_id === goods.goods_id)
      
      if(findResult){
        findResult.goods_count = goods.goods_count
        this.commit('m_cart/saveToStorage')
      }
      
    },
    //根据Id删除对应的商品
    removeGoodsById(state,goods_id){
      state.cart = state.cart.filter(x=> x.goods_id  !== goods_id)
      this.commit('m_cart/saveToStorage')
    
    },
    //更新购物车中所有商品的勾选状态
    updateAllGoodsState(state,newState){
      state.cart.forEach(x => x.goods_state = newState )
      
      this.commit('m_cart/saveToStorage')
      
    }
    
    
  },
  
  
  getters: {
    //购物车中所有商品的总数量
    total(state){
      // let c = 0
      // state.cart.forEach(x => c += x.goods_count)
      // return c
      return state.cart.reduce((total,item) => total += item.goods_count,0)
      
      
    },
    //购物车中已勾选商品的总数量
    checkedCount(state){
      return state.cart.filter(x => x.goods_state).reduce((total,item) =>total += item.goods_count,0)
    },
    //已勾选商品的总价格
    checkedGoodsAmount(state){
      return state.cart.filter(x => x.goods_state).reduce((total,item) => total += item.goods_count * item.goods_price,0).toFixed(2)
      
    }
    
    
  }
  
  
}